1. Field of the Invention
The present invention relates to an automatic telephone answering apparatus and, more particularly, to an automatic telephone answering apparatus having an outgoing message function and a private message function.
2. Description of the Prior Art
In a so-called automatic telephone answering apparatus which is capable of recording incoming messages while a subscriber is out, when an incoming call is received, an outgoing answering message is first sent instructing the caller to record his or her incoming message, and thereafter, this incoming message is actually recorded. An automatic telephone answering apparatus of this type can have a private message function for allowing a caller (e.g., a mother) to leave a private outgoing message to a specific person (e.g., her child).
In a conventional automatic telephone answering apparatus having outgoing and private message functions, a cassette tape or a memory integrated circuit (IC) is mainly used as the medium for recording the above messages. In order to record an outgoing message or a private message on the recording medium, these messages are recorded on a cassette tape, or only the outgoing message is stored in the memory IC and only the private and incoming messages are recorded on the cassette tape. Alternatively, both the outgoing and incoming messages are stored in the memory IC.
In an automatic telephone answering apparatus for sequentially recording outgoing, private, and incoming messages all on one magnetic tape, the outgoing message is first reproduced and then the incoming message is recorded. For subsequent calls, the tape must be rewound to the beginning to reproduce the outgoing message and then fast forwarded to the end of the last recorded message before the new message can be recorded. This tape forwarding must also be performed to record a private message. In such case the end position of the outgoing message is often spaced apart some considerable distance along the length of the tape from the start position of the incoming message. Thus, when only a cassette tape is used as the medium for recording the various messages, it takes a long tape forwarding/rewinding time which prolongs the time required for recording the messages, confirmation of the recorded contents, and reproduction of the recorded contents.
In other types of message answering devices which store the outgoing message in a memory IC, and record private and incoming messages on the cassette tape, the outgoing message can be immediately reproduced upon reception of the incoming call, and the incoming message can be immediately recorded after reproduction of the outgoing message.
In order to record the incoming message, however, the cassette tape must still be forwarded from the point where the private message is recorded to a position where the incoming message can be recorded. Therefore, high-speed recording and reproduction cannot be performed for the incoming message.
In those message answering apparatus where both the outgoing and incoming messages are recorded in the memory IC, high-speed recording and reproduction of the incoming message can be achieved, thus solving the above problem. In order to perform this, however, the memory capacity must be greatly increased, and the manufacturing cost is consequently increased. In order to minimize an increase in the required memory capacity, the speech conversion (i.e. sampling) rate can be decreased. However, the quality of the voices is degraded, resulting in an inconvenience.
In still another conventional automatic telephone answering apparatus, an outgoing message is stored in a memory IC, the outgoing message is read out from the memory IC upon reception of an incoming call, and an incoming message can be immediately recorded on a cassette tape. An outgoing message recording area is also assigned to the start portion of the cassette tape, and the outgoing message is written in the memory IC. At the same time, the outgoing message is recorded on the magnetic tape to back up the data stored in the memory IC in case of a power failure.
When recording is performed to update the outgoing message, it can often result in failure due to the presence of ambient noise and unsatisfactory sentences in the new message. In this case, the memory IC and the magnetic tape are operated in the write mode and the recording mode, respectively, and another new message is entirely written or recorded to entirely erase the unsatisfactory outgoing message. Sufficient rewrite time is sometimes unavailable to update the outgoing message from a remote location using, e.g., a telephone set elsewhere. When the rewrite time is insufficient, an unsatisfactory outgoing message may be stored in the memory IC and is recorded on the magnetic tape. In this case, the old outgoing message prior to the updating of the message might be better than the updated unsatisfactory outgoing message. However, the old outgoing message written in the memory IC and the magnetic tape was partially or entirely erased upon writing of the new outgoing message. The old outgoing message cannot be recovered.
When the newly written outgoing message is unsatisfactory, it cannot be updated unless another new message is written over the unsatisfactory message.